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Data Structures for Drivers

scsi_pkt(9S)

INTERFACE LEVEL
DESCRIPTION
STRUCTURE MEMBERS
SEE ALSO

SYNOPSIS

#include <sys/scsi/scsi.h>

A scsi_pkt structure defines the packet that is allocated by scsi_init_pkt(9F). The target driver fills in some information, and passes it to scsi_transport(9F) for execution on the target. The host bus adapter (HBA) fills in some other information as the command is processed. When the command completes (or can be taken no further) the completion function specified in the packet is called, with a pointer to the packet as its argument. From fields within the packet, the target driver can determine the success or failure of the command.

STRUCTURE MEMBERS

opaque_t             pkt_ha_private;                  
                      /* private data for host adapter */
struct scsi_address  pkt_address;                     
                      /* destination packet */
opaque_t             pkt_private;                     
                      /* private data for target driver */
void                 (*pkt_comp)(struct scsi_pkt *);  
                      /* callback */
uint_t                pkt_flags;                       
                      /* flags */
int                  pkt_time;                        
                      /* time allotted to complete command */
uchar_t              *pkt_scbp;                       
                      /* pointer to status block */
uchar_t              *pkt_cdbp;                       
                      /* pointer to command block */
ssize_t              pkt_resid;                       
                      /* number of bytes not transferred */
uint_t               pkt_state;                       
                      /* state of command */
uint_t               pkt_statistics;                  
                      /* statistics */
uchar_t              pkt_reason;                      
                      /* reason completion called */

pkt_ha_private: An opaque pointer that the Host Bus Adapter uses to reference a private data structure used to transfer scsi_pkt requests.
pkt_address: Initialized by scsi_init_pkt(9F); pkt_address records the intended route and recipient of a request.
pkt_private: Reserved for the use of the target driver; pkt_private is not changed by the HBA driver.
pkt_comp: Specifies the command completion callback routine. When the host adapter driver has gone as far as it can in transporting a command to a SCSI target, and the command has either run to completion or can go no further for some other reason, the host adapter driver will call the function pointed to by this field and pass a pointer to the packet as argument. The callback routine itself is called from interrupt context and must not sleep or call any function that might sleep.
pkt_flags: Provides additional information about how the target driver expects the command to be executed. See pkt_flag Definitions.
pkt_time: Will be set by the target driver to represent the maximum time in seconds that this command is allowed to take to complete. Timeout starts when the command is transmitted on the SCSI bus. pkt_time may be 0 if no timeout is required.
pkt_scbp: Points to either a struct scsi_status(9S) or, if auto-rqsense is enabled, and pkt_state includes STATE_ARQ_DONE, a struct scsi_arq_status. If scsi_status is returned, the SCSI status byte resulting from the requested command is available; if scsi_arq_status(9S) is returned, the sense information is also available.
pkt_cdbp: Points to a kernel-addressable buffer whose length was specified by a call to the proper resource allocation routine, scsi_init_pkt(9F).
pkt_resid: Contains a residual count, either the number of data bytes that have not been transferred ( scsi_transport(9F)) or the number of data bytes for which DMA resources could not be allocated scsi_init_pkt(9F). In the latter case, partial DMA resources may only be allocated if scsi_init_pkt(9F) is called with the PKT_DMA_PARTIAL flag.
pkt_state: Has bit positions that represent the six most important states that a SCSI command can go through (see pkt_state Definitions).
pkt_statistics: Maintains some transport-related statistics. (see pkt_statistics Definitions).
pkt_reason: Contains a completion code that indicates why the pkt_comp function was called. See pkt_reason Definitions, below.

The host adapter driver will update the pkt_resid, pkt_reason, pkt_state, and pkt_statistics fields.

pkt_flags Definitions:

The appropriate definitions for the structure member pkt_flags are:

FLAG_NOINTR: Run command with no command completion callback; command is complete upon return from scsi_transport(9F).
FLAG_NODISCON: Run command without disconnects.
FLAG_NOPARITY: Run command without parity checking.
FLAG_HTAG: Run command as the head-of-queue-tagged command.
FLAG_OTAG: Run command as an ordered-queue-tagged command.
FLAG_STAG: Run command as a simple-queue --tagged command.
FLAG_SENSING: Indicates command is a request sense command.
FLAG_HEAD: Place command at the head of the queue.
FLAG_RENEGOTIATE_WIDE_SYNC: Before transporting this command, the host adapter should initiate the renegotiation of wide mode and synchronous transfer speed. Normally the HBA driver manages negotiations but under certain conditions forcing a renegotation is appropriate. Renegotiation is recommended before Request Sense and Inquiry commands. (Refer to the SCSI 2 standard, sections 6.6.21 and 6.6.23.) This flag should not be set for every packet as this will severely impact performance.

pkt_reason Definitions:

The appropriate definitions for the structure member pkt_reason are:

CMD_CMPLT: No transport errors; normal completion.
CMD_INCOMPLETE: Transport stopped with abnormal state.
CMD_DMA_DERR: DMA direction error.
CMD_TRAN_ERR: Unspecified transport error.
CMD_RESET: SCSI bus reset destroyed command.
CMD_ABORTED: Command transport aborted on request.
CMD_TIMEOUT: Command timed out.
CMD_DATA_OVR: Data overrun.
CMD_CMD_OVR: Command overrun.
CMD_STS_OVR: Status overrun.
CMD_BADMSG: Message not command complete.
CMD_NOMSGOUT: Target refused to go to message out phase.
CMD_XID_FAIL: Extended identify message rejected.
CMD_IDE_FAIL: "Initiator Detected Error" message rejected.
CMD_ABORT_FAIL: Abort message rejected.
CMD_REJECT_FAIL: Reject message rejected.
CMD_NOP_FAIL: "No Operation" message rejected.
CMD_PER_FAIL: "Message Parity Error" message rejected.
CMD_BDR_FAIL: "Bus Device Reset" message rejected.
CMD_ID_FAIL: Identify message rejected.
CMD_UNX_BUS_FREE: Unexpected bus free phase.
CMD_TAG_REJECT: Target rejected the tag message.

pkt_state Definitions:

The appropriate definitions for the structure member pkt_state are:

STATE_GOT_BUS: Bus arbitration succeeded.
STATE_GOT_TARGET: Target successfully selected.
STATE_SENT_CMD: Command successfully sent.
STATE_XFERRED_DATA: Data transfer took place.
STATE_GOT_STATUS: Status received.
STATE_ARQ_DONE: The command resulted in a check condition and the host adapter driver executed an automatic request sense command.

pkt_statistics Definitions:

The definitions that are appropriate for the structure member pkt_statistics are:

STAT_DISCON: Device disconnect.
STAT_SYNC: Command did a synchronous data transfer.
STAT_PERR: SCSI parity error.
STAT_BUS_RESET: Bus reset.
STAT_DEV_RESET: Device reset.
STAT_ABORTED: Command was aborted.
STAT_TIMEOUT: Command timed out.

NAME

SYNOPSIS

INTERFACE LEVEL

DESCRIPTION

STRUCTURE MEMBERS

pkt_flags Definitions:

pkt_reason Definitions:

pkt_state Definitions:

pkt_statistics Definitions:

SEE ALSO